Is this build failure Windows specific? I just updated and built my "clean" sandbox on Linux and I didn't see any problems.

My guess is that this is something to do with the classlib JAR file. Someone who is experiencing this problem please check that the JAR file has been correctly downloaded, unpacked to the correct location, and that the jar utility can see the "java.lang.Object" class in the JAR file.

... and that the jar utility can see the "java.lang.Object" class in the JAR file.

For example, on linux I would run:

jar -tvf classlib.jar | grep "java/lang/Object"

In other words, use "jar -tvf" to list the JAR file and look for the 'Object' class in the listing. I'm not a Windows developer, so I won't attempt to tell you how to do the above at the windows command prompt.